This test just was relanded :( https://crrev.com/c/1345248
I will revert it

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b6bfa2b7f9065773ba9df3b492e4cc5559e4e785

commit b6bfa2b7f9065773ba9df3b492e4cc5559e4e785
Author: Christian Dullweber <dullweber@chromium.org>
Date: Thu Nov 22 10:42:47 2018

Revert "Reland "Update BrowsingDataRemoverBrowserTest to include MediaLicenses""

This reverts commit a4831e9b528dba6992024d0f2242f3b1bad07f9a.

Reason for revert: still flaky :(

Original change's description:
> Reland "Update BrowsingDataRemoverBrowserTest to include MediaLicenses"
> 
> Original change's description:
> > MediaLicenses can be cleared from the ClearBrowsingData dialog, so update the
> > BrowsingDataRemoverBrowserTest to check them as well. This uses the test-only
> > External Clear Key CDM to store the license in the file system, if it is
> > available.
> 
> This reverts commit e9fc38c7b46443cb953b7676fe0f4e82c3d9c0dc.
> 
> The original CL was flaky due to Mac's only saving file timestamps to
> second granularity. As a result it was possible for the newly created license
> to be saved with a timestamp prior to the current actual time, and deleting
> "old" licenses would include it in the deletion. Change is to wait for some
> time on Macs only to ensure that the "new" license has a later timestamp.
> 
> BUG=808690, 879812 
> TEST=new browser_tests pass
> 
> Change-Id: Ibd7cf65b468f98af9aa583d3f320e54c8f3f223e
> Reviewed-on: https://chromium-review.googlesource.com/c/1345248
> Reviewed-by: Christian Dullweber <dullweber@chromium.org>
> Commit-Queue: John Rummell <jrummell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#610211}

TBR=jrummell@chromium.org,dullweber@chromium.org

Change-Id: I31ee32ae7bb490ce799c92244f352e5a9a627552
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 808690,  879812 ,  907799 
Reviewed-on: https://chromium-review.googlesource.com/c/1347367
Reviewed-by: Christian Dullweber <dullweber@chromium.org>
Commit-Queue: Christian Dullweber <dullweber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610369}
[modify] https://crrev.com/b6bfa2b7f9065773ba9df3b492e4cc5559e4e785/chrome/browser/browsing_data/browsing_data_remover_browsertest.cc
[delete] https://crrev.com/ea9f7c1f73dbe189791ad403b351540620d4ef8b/content/test/data/browsing_data/media_license.html

Great, thanks.

Sleep(1) in tests, what could possibly go wrong. ;)

Yep, I guess we need a properly mocked clock for this